What is a terabyte?

In 1955, IBM presented the first computer that used data on permanent storage. The storage capacity at the time was 4 megabytes (MB). Today, this memory capacity wouldn’t even be enough for a smart­phone. Apps, documents, pictures, and other data require sig­nif­i­cant­ly higher data ca­pac­i­ties. As tech­nolo­gies developed, the data units evolved to represent larger data quan­ti­ties in legible numbers. Today, the average person en­coun­ters gigabytes and terabytes on a regular basis. Find out more about these units of in­for­ma­tion and how they’re converted.

Whether smart­phone, laptop, or USB stick – we use a variety of options to store our data. The dig­i­ti­za­tion of content has increased the demand for ever more storage capacity. The amount of data a medium can store is specified in the unit of bytes. This is the smallest possible amount of data. In order to avoid in­com­pre­hen­si­bly long numbers, large amounts of data are des­ig­nat­ed with decimal prefixes. One terabyte therefore cor­re­sponds to 10,000,000,000,000 bytes. However, since computers work with a binary system based on the base 2 (2^x) instead of 10 (10^x), the con­ver­sion factor between in­di­vid­ual units is not 1,000, but 1,024 (2¹⁰). A terabyte therefore comprises 1,099,511,627,776 bytes.

There’s a big dif­fer­ence between terabytes and terabits, despite the near-identical name. To dif­fer­en­ti­ate the two, it’s helpful to learn how bits and bytes are defined. A bit is the smallest digital storage unit that can have the status 0 or 1. A byte consists of eight bits and has 256 possible states. With this number of bits, a binary state can be rep­re­sent­ed as a character that’s readable by humans.

In contrast to storage ca­pac­i­ties, the speed of data transfer is typically specified in bits. The most common unit for this is megabits per second (Mbit/s). But tech­nolo­gies continue to evolve. In ex­per­i­ments, re­searchers have now enabled a trans­mis­sion of 44.2 terabits per second. This means that 1,000 films in HD quality can be down­loaded in just a few seconds.

Terabytes are currently the largest unit of in­for­ma­tion for day-to-day use. Main­frames and server centers, on the other hand, require ca­pac­i­ties that sometimes go well beyond the range of terabytes. The factor 1,024 is decisive for con­vert­ing one unit to the next larger one. The following table provides an overview of the units of in­for­ma­tion and their re­la­tion­ship to one terabyte:

Tech­nolo­gies continue to evolve and so do their storage ca­pac­i­ties. But despite in­creas­ing ca­pac­i­ties, the hardware itself is shrinking. Today, 1 or 2 terabyte hard drives are both compact and af­ford­able. Micro SD cards or USB sticks already offer up to 1 TB of space. In many cases, however, the spec­i­fi­ca­tion in gigabytes is still common for these storage media. It’s likely only a matter of time before terabytes will become ubiq­ui­tous for these storage devices.